3 broken versions for sqlite

diff --git a/src/datastore/plugin_datastore_sqlite.c b/src/datastore/plugin_datastore_sqlite.c
index 3d2a1bb068751cbb97c79ad0b070f255837322a0..1e1f4d87b26a10439c8491cd7a972c0d1a1668cb 100644 (file)
--- a/src/datastore/plugin_datastore_sqlite.c
+++ b/src/datastore/plugin_datastore_sqlite.c
@@ -167,19 +167,32 @@ static void
 create_indices (sqlite3 * dbh)
 {
   /* create indices */
-  sqlite3_exec (dbh,
-                "CREATE INDEX idx_hash ON gn090 (hash)", NULL, NULL, NULL);
-  sqlite3_exec (dbh,
-                "CREATE INDEX idx_hash_vhash ON gn090 (hash,vhash)", NULL,
-                NULL, NULL);
-  sqlite3_exec (dbh, "CREATE INDEX idx_expire_repl ON gn090 (expire ASC,repl DESC)", NULL, NULL,
-                NULL);
-  sqlite3_exec (dbh, "CREATE INDEX idx_comb ON gn090 (anonLevel ASC,expire ASC,prio,type,hash)",
-                NULL, NULL, NULL);
-  sqlite3_exec (dbh, "CREATE INDEX idx_expire ON gn090 (expire)",
-                NULL, NULL, NULL);
-  sqlite3_exec (dbh, "CREATE INDEX idx_repl_rvalue ON gn090 (repl,rvalue)",
-                NULL, NULL, NULL);
+  if ( (SQLITE_OK !=
+       sqlite3_exec (dbh,
+                     "CREATE INDEX IF NOT EXISTS idx_hash ON gn090 (hash)", NULL, NULL, NULL)) ||
+       (SQLITE_OK !=
+       sqlite3_exec (dbh,
+                     "CREATE INDEX IF NOT EXISTS idx_hash_vhash ON gn090 (hash,vhash)", NULL,
+                     NULL, NULL)) ||
+       (SQLITE_OK !=
+       sqlite3_exec (dbh, "CREATE INDEX IF NOT EXISTS idx_expire_repl ON gn090 (expire ASC,repl DESC)", NULL, NULL,
+                     NULL)) ||
+       (SQLITE_OK != 
+       sqlite3_exec (dbh, "CREATE INDEX IF NOT EXISTS idx_comb ON gn090 (anonLevel ASC,expire ASC,prio,type,hash)",
+                     NULL, NULL, NULL)) ||
+       (SQLITE_OK != 
+       sqlite3_exec (dbh, "CREATE INDEX IF NOT EXISTS idx_expire ON gn090 (expire)",
+                     NULL, NULL, NULL)) ||
+       (SQLITE_OK !=
+       sqlite3_exec (dbh, "CREATE INDEX IF NOT EXISTS idx_repl_rvalue ON gn090 (repl,rvalue)",
+                     NULL, NULL, NULL)) ||
+       (SQLITE_OK !=
+       sqlite3_exec (dbh, "CREATE INDEX IF NOT EXISTS idx_repl ON gn090 (repl DESC)",
+                     NULL, NULL, NULL)) )
+    GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
+                    "sqlite",
+                    "Failed to create indices: %s\n",
+                    sqlite3_errmsg (dbh));
 }
 
 
@@ -313,10 +326,42 @@ database_setup (const struct GNUNET_CONFIGURATION_Handle *cfg,
       (sq_prepare (plugin->dbh,
                    "UPDATE gn090 SET repl = MAX (0, repl - 1) WHERE _ROWID_ = ?",
                    &plugin->updRepl) != SQLITE_OK) ||
+#if 1
+      /* FIXME: this is the O(n) version */
+       (sq_prepare (plugin->dbh,
+                   "SELECT type,prio,anonLevel,expire,hash,value,_ROWID_ FROM gn090"
+                   " ORDER BY repl DESC, Random() LIMIT 1",
+                   &plugin->selRepl) != SQLITE_OK) ||
+#elif 0
+      /* FIXME: this gives O(n) queries, presumably because the LEFT JOIN generates
+        a temporary table with all matching expressions before the ORDER BY and LIMIT
+        clauses are applied */
       (sq_prepare (plugin->dbh,
-                  "SELECT type,prio,anonLevel,expire,hash,value,_ROWID_ FROM gn090"
-                  " ORDER BY repl DESC, Random() LIMIT 1",
+                  "SELECT type,prio,anonLevel,expire,hash,value,gn090._ROWID_ "
+                  "FROM (SELECT random() AS v) AS t1,"
+                  "     (SELECT MAX(repl) AS m FROM gn090 INDEXED BY idx_repl) AS t2 "
+                  "     LEFT JOIN gn090 INDEXED BY idx_repl_rvalue"
+                  "     ON repl=t2.m AND"
+                  "        (rvalue>=t1.v OR"
+                  "        NOT EXISTS (SELECT 1 FROM gn090 INDEXED BY idx_repl_rvalue WHERE repl=t2.m AND rvalue>=t1.v))"
+                  "     ORDER BY rvalue ASC"
+                  "     LIMIT 1 ",
                    &plugin->selRepl) != SQLITE_OK) ||
+#else
+      /* NOTE: this fails, because sqlite doesn't link the t2.m (or the t1.v) to the temporary result from before 
+        (parse error during preparation) */
+      (sq_prepare (plugin->dbh,
+                  "SELECT type,prio,anonLevel,expire,hash,value,_ROWID_ "
+                  "FROM (SELECT random() AS v) AS t1,"
+                  "     (SELECT MAX(repl) AS m FROM gn090 INDEXED BY idx_repl) AS t2, "
+                  "     (SELECT type,prio,anonLevel,expire,hash,value,_ROWID_ FROM gn090 INDEXED BY idx_repl_rvalue"
+                  "        WHERE repl=t2.m AND" /* "no such column: t2.m" */
+                  "           (rvalue>=t1.v OR"
+                  "               NOT EXISTS (SELECT 1 FROM gn090 INDEXED BY idx_repl_rvalue WHERE repl=t2.m AND rvalue>=t1.v))"
+                  "      ORDER BY rvalue ASC"
+                  "      LIMIT 1)",
+                   &plugin->selRepl) != SQLITE_OK) ||
+#endif
       (sq_prepare (plugin->dbh,
                   "SELECT type,prio,anonLevel,expire,hash,value,_ROWID_ FROM gn090 "
                   " WHERE NOT EXISTS (SELECT 1 FROM gn090 WHERE expire < ?1 LIMIT 1) OR expire < ?1 "